SUMMARY: "panic: free: freeing free frag"

From: Hans C Larsson (hans@smab.se)
Date: Mon May 03 1993 - 10:57:51 CDT


ORIGINAL PROBLEM:

4/670MP crashes with "panic: free: freeing free frag".

The crash seems to be quota induced, when quota is disabled
the machine just keeps ticking.

MY SETUP:

4/670MP (1*2Ross), 4.1.3 UFS & NFS jumbo patches,
DiskSuite 1.0 with striped metadisk, tmpfs(4S).
(Respondents setups *similar*.)

BUG NUMBER: 1108897

FEEDBACK/CONCLUSIONS/ASSUMPTIONS:

Several people has been bitten by this bug,
two of them had *not* quotas enabled.

It definitely seems load related, i.e. it occurs during high loads.

A theory (of mine) is that quotas makes things worse.

One person had "sun4m jumbo patch"/100726-05 installed and was
waiting to see if it helped.

sutela@Mirfak.cc.utu.fi (Kari Sutela) had gotten a
*VERY UNOFFICAL* adb(1) patch from his local support center
which seems to keep the bug away (see below!).

WHAT HAVE I DONE:

(Taken a deep breath &) patched the running kernel with adb(1)
and so far the machine is running excellent (I did this on april 28).

Made a kernel incorporating "sun4m jumbo patch"/100726-05 and the
adb(1) patch. I will reboot the machine with this kernel next week.

THE ADB(1) PATCH:

***At your own risk***

On a sun4c or sun4m with 4.1.3 only !

For a running kernel:
        $ cp /vmunix /vmunix.sav
        $ adb -k -w /vmunix /dev/mem
        rwip+534?W 0x90900000
        rwip+534/W 0x90900000
        ^D

The first adb line patches the vmunix file & the second patches
the running kernel image in memory.

For a new kernel (not running yet):
        $ adb -w ./vmunix
        rwip+534?W 0x90900000
        ^D

THANKS TO:
        nash@gondor.sdsu.edu (Ron Nash),
        sutela@Mirfak.cc.utu.fi (Kari Sutela),
        "J. Porter Clark" <jpc@avdms8.msfc.nasa.gov>,
        Lynton Willson <lwillson@laurel.ocs.mq.edu.au>,
        per@erix.ericsson.se (Per Hedeland)

SUN, READ THIS: coordinate you support centers please.

-- 
        Hans C Larsson			Email:		hans@smab.se
	Saab Missiles			Motto:		yes
	Sweden				Disclaimers:	oh yes



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